What means this: "Thread 1: "-[First_App.ProximitySensorViewController proximityChanged:]: unrecognized selector sent to instance 0x14d707940""

Question

Hey I'm trying to use the proximity sensor to increase a value, but when I start the function, it crash's. This is my Code, can someone help me?

func proximityChanged(notification: NSNotification) {
            let device = notification.object as? UIDevice
            if device?.proximityState == true {
                print("\(device) detected!")
                count += 1
                updateCountLabel()
            } else {
                print("Error")
            }
        }
        
        
        func activateProximitySensor() {
            let device = UIDevice.current
            device.isProximityMonitoringEnabled = true
            if device.isProximityMonitoringEnabled {
                NotificationCenter.default.addObserver(self, selector: Selector(("proximityChanged:")), name: NSNotification.Name(rawValue: "UIDeviceProximityStateDidChangeNotification"), object: device)
                
            }
        }

Answer 1

I think you might be using old syntax for swift. I have tried to use proximity using below code and is working without crash.

func activateProximitySensor() {
    let device = UIDevice.current
    device.isProximityMonitoringEnabled = true
    if device.isProximityMonitoringEnabled {
        NotificationCenter.default.addObserver(self, selector: #selector(proximityChanged(notification:)), name: UIDevice.proximityStateDidChangeNotification, object: device)
    }
}

@objc func proximityChanged(notification: NSNotification) {
    if let device = notification.object as? UIDevice {
        if device.proximityState {
            print("\(device) detected!")
            count += 1
            updateCountLabel()
        }
    }
}